The major aims of the study are: 1. The correlation between the chromosomal findings of early bladder lesions, primarily papillary tumors, with the cytologic picture and clinical course. 2. A correlation of the karyotypic picture in advanced cancer of the bladder with response to therapy and the clinical course, e.g., sensitivity to X-ray or chemotherapy, metastatic spread, recurrences, etc. Particular emphasis is being put on the banding patterns of the chromosomes in order to ascertain possible early karyotypic lesions which may be indicative of changed tumor behavior, particularly of papillary tumors.